Usb Port? Webcam Issue.

I Own An Acer Aspire 2930 Laptop, Over 2 Yrs. Old., Windows Vista. The Internal Webcam That It Came With Has A Busted Or Broke Cable, So The Tech Repair Told Me To Get External Cam. I Purchased In 2010 From Best Buy A Dynex External Cam For $45, And Geek Squad Installed. I Must Of Used It 20 Times And Recently And Sometime When I Would Plug It In On Left Side It Would Cause My Computer To Shut Down, Screen Go Black And A Ringing Dinging Sound Would Start. I Even Had To Go Into Restore,am Fine Now. But Am Scared To Use Cam Again. Is This A Usb Port Issue? I Was Just Going To Get Another Cam That Would Be Comatible With Yahoo Messenger, A Logitech, Unless There Is Something More Compatible With My Computer. If Port Is Broke Or Lose What Am I Looking At Financially? Thank U